TMS Case Studies

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5. Tank inspection expert Jay Hoffman of Wet or Dry Tank Inspection, Campbells- burg, Ky., recommended the TMS for Morehead’s standpipe and has had the system specified on three other Kentucky tanks that are scheduled to undergo rehabilitation later in 2001. "We’ve tried some mechanical systems in other tanks, but they haven’t worked properly, most likely due to human error on the part of the tank operators," Hoffman said. "The TMS is ideal because it works on its own – it doesn’t require an operator." Since the develop- ment of the TMS, Hoffman has explored no other options for eliminat- ing stagnation in reservoirs. "[The TMS] just works," he said. Red Valve was able to address another potential hazard with the Morehead standpipe’s overflow pipe. Operators often have problems with birds and rodents entering reservoirs through overflow pipes and contaminating the water, and many attempt to control the pests by installing nylon screens and/or metal flapgate valves at the pipe ends. Screens, however, can han- dle very little pressure and are often dislodged in the event of an overflow, and metal flapgates that are exposed to the elements are subject to freezing, warping and rust. Red Valve recom- mended another six-inch Tideflex ® valve at the end of the overflow pipe, which would keep birds and rodents out of the pipe while still allowing water to drain freely. Red Valve Company, Inc. • 700 North Bell Avenue, Carnegie, PA 15106 • 412-279-0044 • Fax 412-279-7878 • To eliminate the potential for thermal stratifi- cation, Red Valve designed a vertical riser pipe with a single inlet valve. A six-inch Tideflex ® on the overflow pipe prevents the intrusion of birds and rodents. MEASURIT

2. was installed in several reservoirs and had proven its mixing efficiency. Knowing that SCWA could save nearly $80,000 by eliminating one expensive excavation and reducing piping requirements to a single manifold, Red Valve suggested the TMS. In keeping with a current trend in potable-water storage, SCWA had switched from chlorine to chlo- ramine as its primary disinfectant in the circular, steel tank. Though a better disinfectant overall, chloramine has its drawbacks, including a greater risk of the formation of contaminating byproducts and a higher susceptibility to stratification. Furthermore, the slight ammonia concentration in chloramine will erode some process equipment, especially certain types of rubber. In addition to providing significant cost savings for SCWA, Red Valve was able to address these chal- lenges with the TMS. Because the Tideflex ® is a vari- able-orifice valve that maximizes jet velocity, the TMS provides the best possible mixing characteris- tics. Moreover, having dealt with chloramine in the past, Red Valve had already determined that its NSF-61-approved SBR elastomer was not affected by ammonia. Like many tank operators on the west coast, the Sonoma County Water Agency (SCWA) in Sonoma County, Calif., chose to perform major rehabilita- tions, including state-mandated seismic upgrades, to its existing finished water reservoirs. State seis- mic regulations require inlet/outlet protrusions to be located at a tank’s sides and attached to piping with special ball-and-socket joints that are flexible enough to prevent breakage during earthquakes. In 1998, SCWA completely overhauled one of its six- million-gallon, ground-level reservoirs. To fill and drain, the rehabilitated tank uses two protrusions located at opposite ends of the tank, a complex pip- ing system and two 30-inch Tideflex ® Series 39F InLine Check Valves from Red Valve. While this fill- and-drain system is sufficient for preventing stag- nation, a second protrusion in a tank is a major and expensive alteration; the additional ball-and-socket joint alone cost SCWA approximately $25,000. When SCWA launched plans to overhaul an adja- cent tank of the same size and shape a year later, the utility intended to use a similar fill-and-drain con- figuration and again contacted Red Valve for the purchase of two InLine Check Valves. By this time, the TMS, which requires only one tank protrusion, Red Valve Company Case Study Red Valve Company, Inc. • 700 North Bell Avenue, Carnegie, PA 15106 • 412-279-0044 • Fax 412-279-7878 • Sonoma County, Calif., installs Tideflex ® Mixing System (TMS) in 6,000,000-gallon, ground-level reservoir Two 24-inch fill valves provide efficient mixing in this 6,000,000-gallon tank, which contains chloramine. Maximizing the distance between the inlet and outlet without drilling a second protrusion saved the county nearly $80,000. MEASURIT

1. The City of Centreville, Md., purchased a 100,000-gal- lon elevated spheroid tank from a neighboring city. The used tank was deconstructed and shipped to Centreville to be re-erected as a backup reservoir, pri- marily to meet high summer demands. Because the reservoir was not expected to see a lot of turnover, City Manager Terry Adams was concerned about the potential for stagnation, especially during the winter months. Having seen an advertisement for Red Valve’s TMS, Adams instructed the city contractor, R&S Development of Centreville, to install the system before re-erecting the tank. Because no consult- ant was involved in the job, Red Valve used its engineering expertise to design the entire system, including the length of the manifold, the configuration of the inlet and outlet and the size and material of the Tideflex ® valves. Red Valve also sup- plied all materials for Centreville’s TMS . Red Valve Company Case Study Red Valve Company, Inc. • 700 North Bell Avenue, Carnegie, PA 15106 • 412-279-0044 • Fax 412-279-7878 • City of Centreville, Md., installs Tideflex ® Mixing System (TMS) in 100,000-gallon elevated tank The city of Centreville purchased this used 100,000- gallon elevated spheroid from a neighboring city. Red Valve designed and supplied the entire Tideflex ® Mixing System. MEASURIT

3. After seeing an advertisement for the TMS, the Hixson Utility District (HUD) in Hixson, Tenn., con- tacted Red Valve in January of 2001 with the inten- tion of including the system in the upgrade of its 1,000,000-gallon standpipe. One month later, HUD had placed the order, and construction was under- way on this fast-paced project. The standpipe contains one protrusion that was being used as a common inlet and outlet, and water flows in and out of the tank at a virtually constant rate. "We had very little fluctuation in the tank level and practically no turnover," said HUD’s Tom Bockman. "Our chlorine residuals weren’t a serious problem, but state limits are getting tougher. This was a proactive approach." According to Bockman, HUD has been searching for a solution to its turnover situation for nearly four years, during which time they explored several options. They con- sidered a second protrusion in the tank, but this would have required the utility to run a huge piping loop around an existing building and uproot an entire treatment plant, among other incon- veniences. "With all of the additions, including all the extra piping inside the tank, it would have been a lot more expensive," Bockman said. To ensure the best mixing in HUD’s 56-foot-high tank, Red Valve designed a system with two sets of three eight-inch fill valves set 10-feet apart on a ver- tical riser pipe. Tall tanks are prone to slight level fluctuations, and water discharging from non-sub- merged valves cannot achieve maximum jet veloci- ty. With two sets of valves, the lower set is likely to be always under water, while the higher set still pro- tects against any possibility of short-circuiting. By delivering the system in stages, Red Valve was able to keep pace with HUD’s goal to have the tank online and operating by June 2001. Red Valve Company Case Study Red Valve Company, Inc. • 700 North Bell Avenue, Carnegie, PA 15106 • 412-279-0044 • Fax 412-279-7878 • Tideflex ® Mixing System (TMS) eliminates stagnation in 1,000,000-gallon standpipe in Hixson, Tenn. Red Valve spread two sets of inlets 10 feet apart to ensure proper mixing and still eliminated short-circuiting. The L-shaped manifold was welded to the single protrusion near the tank bottom. Saddle Support Technology was provided to increase the maximum backpressure capacity of the 16-inch drain valves. MEASURIT

4. As part of a $150,000 upgrade to its 100,000- gallon steel standpipe, the Morehead Utility in Morehead, Ky., responded to encourage- ment from its consultants and the State of Kentucky and decided to install a mixing system to avoid stag- nation within the tank. The tank had a slight stagnation problem prior to the upgrade, and a sys- tem that had no mechanical parts and would operate pas- sively was appealing to the city. "The State (of Kentucky) is pushing for all tanks to incorpo- rate an automatic turnover sys- tem to avoid stagnation; in fact, all new tanks are now required to have a separate inlet and out- let," said Consultant Doug Baldwin of Lexington-based Commonwealth Technologies. Red Valve Company Case Study Red Valve Company, Inc. • 700 North Bell Avenue, Carnegie, PA 15106 • 412-279-0044 • Fax 412-279-7878 • Tideflex ® Mixing System (TMS) eliminates stagnation in 100,000-gallon standpipe in Morehead, Ky. "A submersible system with no working parts or gears is perfect because it leaves no potential for hazards." Morehead’s standpipe has a height of 22 feet, making it susceptible to thermal strat- ification, in which water at the top of the tank never receives the cooling effect of incoming fresh water. Red Valve recog- nized the potential problem and designed a TMS with a vertical riser pipe and one six- inch fill valve that would discharge near the top of the tank. This way, discharging water must flow through the depth of the tank before draining, resulting in better overall circulation. Morehead’s 100,000-gallon tank is 20 years old. Two 6” Series 37s in cross at bottom of tank that function as outlets MEASURIT


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